Originally Posted by
zeltergiset
Definitely quicker to take airside bus to T3. Once you get to T3, you are able to exit through T3 arrivals & re-enter if transfer security looks busy.
I agree.
The slight nuance is that being a DUB flight you can get landside extra quick, almost as quick as Domestic, with no passport check, so if you smoke or have some other reason to be landside it won't detain you so much to go landside. But I would still advocate using the airside bus.